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单位8亿多条的日志表，经过自动分表之后，需要自动删除30天前创建的日志表。 但是只是在Master下线这些日志表，而Slave还需要保持在线，以备查询。 由于Master-Slave结构，在Drop表之前，设置@@session.sql_log_bin=0,那么Drop的行为就没有记录到binlog，所以Slave的日志表就会被保留。 模拟环境如下, mysql> show tables; +---------------------------------+ | Tables_in_edmond | +---------------------------------+ | sod_song_log_2014_1_22_13_18_20 | | sod_song_log_2014_2_22_13_18_20 | | sod_song_log_2014_3_22_13_18_20 | | sod_song_log_2014_4_22_13_18_20 | +---------------------------------+ 4 rows in set (0.00 sec) delimiter $$ CREATE procedure drop_table() BEGIN declare t_name varchar(64); declare isFinished int default false; declare log_table_list cursor for (select table_name from information_schema.tables where table_schema = 'EDMOND' and table_name like 'sod_song_log_%'); declare continue handler for not found set isFinished=true; open log_table_list; repeat fetch log_table_list into t_name; if isFinished = false then if datediff(now(),replace(t_name,'sod_song_log_',''))>30 then set @@session.sql_log_bin=0; set @sqltext=concat('drop table ',t_name,';'); PREPARE c_tab_stat from @sqltext; execute c_tab_stat; set @@session.sql_log_bin=1; end if; end if; until isFinished end repeat; close log_table_list; END $$ delimiter ; mysql> call drop_table(); Query OK, 0 rows affected (0.28 sec)
mysql> show tables; +---------------------------------+ | Tables_in_edmond | +---------------------------------+ | sod_song_log_2014_4_22_13_18_20 | +---------------------------------+ 1 row in set (0.00 sec)
mysql> select now() from dual; +---------------------+ | now() | +---------------------+ | 2014-04-22 17:58:24 | +---------------------+ 1 row in set (0.00 sec) 配合Linux crontab即可实现定期自动删除表的功能。 一定不要把sql_log_bin设置为global级别,不能犯迷糊 |
